scholarly journals Effects of water content, water type and temperature on the rheological behaviour of slag-cement and fly ash-cement paste backfill

2020 ◽  
Vol 30 (3) ◽  
pp. 271-278 ◽  
Author(s):  
Yue Zhao ◽  
Abbas Taheri ◽  
Murat Karakus ◽  
Zhongwei Chen ◽  
An Deng
2013 ◽  
Vol 486 ◽  
pp. 319-322
Author(s):  
Ondřej Zobal ◽  
Pavel Padevět

Above average amount of fly ash production in the Czech Republic compels us to process it. Part of this waste material has some potential for use in various industries. The largest part is used in construction. One option is the use of larger replacement of cement with fly ash than as required by current standards. This paper is dedicated to the cement paste with different fly ash cement replacement. Specifically, are observed properties of hardened mixtures depending on the water content. There are presented the results of measurements of volume density and compressive strength.


2017 ◽  
Vol 744 ◽  
pp. 146-151
Author(s):  
Ming Qing Huang ◽  
Xiao Hui Liu ◽  
Hai Yong Cheng

To produce effective cement paste backfill materials at iron mines technologically and economically, orthogonal experiments of mix proportions with extra-fine unclassified tailings were carried out. The results of the range analysis showed that the sensitivity of influential factors to the slurry slump is sequentially mass concentration, tailing/rock ratio, and cement/(tailing+rock) ratio. The sensitivity to bleeding rate, concretion time and 28-day uniaxial compressive strength is sequentially mass concentration, cement/(tailing+rock) ratio and tailing/rock ratio. Relationships of paste properties and influential factors can be demonstrated with regression analysis. Additionally, the optimal mix proportion for cement paste backfill was obtained with 78% mass concentration, 7:3 tailing/rock ratio and 1:25 cement/(tailing+rock) ratio. The slump, bleeding rate, concretion time and R28 of the optimal mixture are 25.2 cm, 8.77%, 20.9 h and 1.29 MPa, respectively. The experimental results show a feasible way to produce the industry standard backfilling materials.


2016 ◽  
Vol 70 (1) ◽  
pp. 141-147
Author(s):  
Yuko OGAWA ◽  
P. Trinh BUI ◽  
Kenji KAWAI ◽  
Kazuki OTAISHI

Author(s):  
Yibiao Teng ◽  
Songhui Liu ◽  
Zhaocai Zhang ◽  
Jiangwei Xue ◽  
Xuemao Guan

2013 ◽  
Vol 357-360 ◽  
pp. 968-971 ◽  
Author(s):  
Ren Juan Sun ◽  
Zhi Qin Zhao ◽  
Da Wei Huang ◽  
Gong Feng Xin ◽  
Shan Shan Wei ◽  
...  

The effect of fly ash and nanoCaCO3 on the viscosity of pastes was studied. The rheological value of cement paste was determined by the rotation rheometer NXS-11B. In the study, five different dosages (0%, 20%, 30%, 40%, and 50%) of fly ash and three levels of nanoCaCO3, 0.5%, 1%, and 2.5%, were considered. Viscosity of the pastes, made with fly ash and nanoCaCO3 at a constant water-to-binder ratio of 0.35, were measured and analyzed. The results indicate that the pastes with fly ash or/and nanoCaCO3 still fit the Bingham model. The addition of fly ash reduced viscosity, however, the addition of nanoCaCO3 increased viscosity. The effect of nanoCaCO3 is more significantly than fly ash on viscosity.


2014 ◽  
Vol 584-586 ◽  
pp. 894-898
Author(s):  
Ping Zhang ◽  
Guan Guo Liu ◽  
Chao Ming Pang ◽  
Bing Du ◽  
Hong Gen Qin

The X ray computed tomography (X-CT) was applied to test the cracking resistance of cement paste, and the hydration process was monitored to study the effect of fly ash on the early age cracking performance. The results showed that the hydration heat reduced with the increase of fly ash under the same water-cement ratio. Within 24h, the porosity increased with time. The addition of fly ash increased the proportion of large holes and then changed the internal stress state. Using X-CT test method and by comparing the number of cracks, the sample with 20% FA was found to have the most serious cracks, whereas the sample with 30% FA had the best crack resistance.


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